US 7,402,516 B2 · Method for making integrated circuits

Abstract

Integrated circuits, the key components in thousands of electronic and computer products, include interconnected networks of electrical components. The components are typically wired, or interconnected, together with aluminum wires. In recent years, researchers have begun using copper instead of aluminum to form integrated-circuit wiring, because copper offers lower electrical resistance and better reliability at smaller dimensions. However, copper typically requires use of a diffusion barrier to prevent it from contaminating other parts of an integrated circuit. Unfortunately, typical diffusion barrier materials add appreciable resistance to the copper wiring, and thus negate some advantages of using copper. Moreover, conventional methods of forming the copper wiring are costly and time consuming. Accordingly, the inventors devised one or more exemplary methods for making integrated-circuit wiring from materials, such as copper-, silver-, and gold-based metals. One exemplary method removes two or more masks in a single removal procedure, forms a low-resistance diffusion barrier on two or more wiring levels in a single formation procedure, and fills insulative material around and between two or more wiring levels in a single fill procedure. This and other embodiments hold the promise of simplifying fabrication of integrated-circuit wiring dramatically.

Claims30

Dependent claims

A method of making an integrated circuit, comprising:

forming a first mask layer having a first plurality of openings on a semiconductor substrate having at least one transistor structure and an insulator layer having a predetermined vertical thickness to form an access to selected portions of the at least one transistor;
forming a second mask layer having a second plurality of openings;
removing a portion of the insulator layer to expose the selected portions of the at least one transistor;
forming a first conductive material layer in the first and second plurality of openings;
forming a second conductive material layer disposed upon the first conductive material and extending upward to a top surface of the second mask layer;
removing substantially all of the first and second mask layers;
and
forming a diffusion barrier layer on substantially all portions of the first and second conductive materials not directly in contact with one of the selected portions of the at least one transistor and the insulator layer.

5 more elements

A method of making an integrated circuit, comprising:

forming a first mask layer having a first plurality of openings;
forming a second mask layer having a second plurality of openings;
forming a first conductive material layer having a thickness of from 20 to 30 nanometers in the first and second plurality of openings;
forming a second conductive material layer having a thickness of from 300 to 600 nanometers upon the first conductive material and extending upward to a top surface of the second mask layer;
forming a third mask layer having a third plurality of openings;
forming a fourth mask layer with a fourth plurality of opening;
forming a third conductive material in the third and fourth plurality of openings and contacting the second conductive material;
forming a fourth conductive material upon the third conductive material and extending upward to a top surface of the fourth mask layer;
removing substantially all of the first, second, third and fourth mask layers;
and
forming a diffusion barrier layer on substantially all portions of the first, second, third and fourth conductive materials not directly in contact with one of the integrated circuit, remaining portions of the first, second, third and fourth mask layers, and portions of other ones of the first, second, third and fourth conductive materials.

8 more elements

Dependencies are inferred from the claim text.

Method for making integrated circuits

Life of this patent

Method for making integrated circuits

Life of this patent

Abstract

Claims30